Core recovering tool



May 25, 1937. AC. CATLAND ET AL CORE RECOVERING TOOL Filed June 21, 1955 2 Sheets-Sheet 1 A TTORNE Y :Patented May 25, 1937 UNITED {STATES-A PATENT OFFICE CORE REOOVERING TOOL Alfred C. Catland, Alhambra, and John H.

Howard, Huntington Park, Calm; said Catland assignor to Globe Oil Tools Company, Lon Nietos, CaliL, a corporation of California Application June 21, 1935, Serial No. 27,704

- 16 Claims.

This invention relates to a well tool and relates more particularly to a well tool for obtaining a core or sample of the earth formation. A general object of this invention is to provide a practical, dependable and particularly efiective tool ings of the inner barrels of such tools have ma terially complicated the general construction of the tools and have necessitated the diverting of the circulation fluid past the rotatable mountings through ports of small diameter and of substantial length. The mud-laden circulation fluid passing through these ports under pressure quickly erodes and wears away the ported parts. Core drills usually embody core catchers and one of the most popular types of core catchers includes a ring-like body having depending springs -carry-. ing gripping slips which are actuated into gripping and holding engagement with the core through cooperation with an inclined surface on the interior of the tool. It has been found that the slips carried by the. depending springs work downwardly on the inclined surface when the tool is being run into the well and are thus in their fully actuated positions before the actual coring operation is begun. As the core enters the tool its upper v end encounters the actuated slips and the core is often destroyed by theslips as the drilling progresses. In other instances, the entering core engaging the slips causes the springs carrying the slips to be bent back upon themselves and broken resulting in the loss of the slips and mutilation and possible loss of the core.

Another object of this invention is to provide a core drill embodying a rotatably supported inner a core drill that embodies a simple, effective means for rotatably supporting the lower end of the inner barrel in the bit head.

core catcher that does not interfere with the encore catcher embodying the novel combination of dogs and the slips remain in their actuated positions the core engaging the slips readily moves core drill of the character mentioned that embodies an improved and simplified means for handling the circulation'fiuid.

Another object of the invention is to provide a trance or passage of the core into the tool and that is capableof dependably recovering and retaining the core with a minimum of mutilation of the core.

. Another object oi'this invention is to provide 10 a core catcher comprising a bodyand slips located above the body and connected therewith by flexible springs or flexible members to be movable inwardly into gripping contact with the core by cooperation with an inclined face of the core drill. The slips of the improved core catcher of this inventionbeing above the core catcher body, as

distinguished from the slipsof the usual core catchers which are below the body, are less liable to mutilate the core as it enters the drill and the engagement of the slips with the entering core 2 does not subject the flexible members to distorting or fracturing strains but merely puts them undertension.

Another object-oi the invention is to provide a 25 of pivoted core-retaining dogs on the core catching body and core gripping slips abovethe body connected therewith-by springs or flexible members. The spring urged pivoted dogs on thebody 0 are engaged by the core as-it enters the drill and this engagement usually moves the core catcher to its inoperative position where the slips are retracted and cannot interfere with the core. In instances where the core passes through the series them to their retracted positions without being mutilated and without injuring the core catcher. Another object of this invention is to provide a core drill of the character mentioned embodying a bearing member on the lower end of the inner barrel for' supporting it for rotation and a core catcher rotatably disposed in the bearing member whereby it may turn or remain stationary with respect to the inner barrel at will during the coring operation.

The various objects and features of our invention will be fully understood from the following detailed description of typical preferred forms and applications of the invention, throughout which description reference is made to the accompanying drawings, in. which:

Fig. 1 is a side elevation of a drill embodying the present invention illustrating the lower major of a well drilling string for operation in a well portion in central vertical cross section. Fig. 2 is an enlarged transverse detailed sectional view taken substantially as-indicated by line 2-2 on Fig. 3. Fig. 3 is an enlarged vertical detailed sectional view of the core catcher, the bearing memberand the adjacent parts. Fig. 4 is an enlarged side elevation of the core catcher removed from the drill with a portion broken away tc'appear in vertical cross section. Fig. 5 is a transverse detailed sectional view of the core catcher taken substantially as indicated by line 5-5 on Fig. 4, and Fig. 6 is an enlarged fragmentary vertical sectional view of an alternative ormodifled construction; Y

The. present invention as illustrated in Figs.

1 to 5, inclusive, of the drawings, includes, generally, an outer barrel l0 having a bit head II on its lower end, an inner barrel l2 rotatably sup- Ported in the bit head H and a core catcher 3.

The outer barrel I0 is an elongate tubular member adapted to be attached to the lower end bore. A tubular connecting member or sub I4 is attaohedto the lower end of the outer barrel ill to form an extension or part thereof. The sub H has a pin IS on its lower end. A bit head sub l3 is'threaded on the pin l5 and is provided with a socket H in its lower end. The. bit head sub l3 constitutes a connecting member for connecting the bit head I with the lower part or sub H of the outer barrel l0.

The bit head includes a tubular body or shoe IS. The shoe I8 has a pin IS on its upper end threaded into the socket H. The longitudinal tion or upper portion of the shoe l8 and has an upwardly facing annular'shoulder 22 on its wall.

The cutting head or bit head I has cutting means for making an annular cut in the earth formation, and for forming a core for reception in the tubular drill. In accordance with the broader aspects of the invention any type or character of cutting means may be embodied in the head II. In the particular embodiment of the invention disclosed in the drawings roller cutters 23 are rotatably supported in pockets or recesses 24 in the lower end of the shoe I3 and project from the lower end of the shoe to act on the formation at the bottom of the well bore. The cutters 23 are operable to make an annular cut in the earth formation as the drill is rotated and trim the core for proper reception in the shoe opening 29.

The inner barrel I2 is arranged longitudinally in the outer barrel l0 and is adapted to receive .the core. The inner barrel I2 is preferably thin walled to be light in weight and is spaced from ber 2| is received in the socket 2| of the shoe l8.

and is adapted to rotatably bear on the shoulder 32 to rotatably support the inner barrel |2. The bearing member 26 extends longitudinally through the sub. IS with considerable clearance leaving an annular fluid passage 21. The upper end portion of the bearing member 26 pref-- 'erably extends upwardly into the-pin l5 to have rotatable bearing engagement with its internal wall. A hardened bushing 23 is provided on the bearing member 23 to bear upwardly against the lower end of the pin I! when the engagement of the core with the inner barrel l2 and its associated parts tends to hold the inner barrel against downward movement while the drill is being fed downwardly into the earth formation. Short ports 29 of substantial fluid capacity are provided in the bearing member 23 to connect the lower 'end of the annular passage 25 with the annular passage 21. In accordance with theinvention the longitudinal opening 30 of the bearing member 23 has an enlarged or recessed portion with a downwardly and inwardly inclined wall or surface 3 I. A counter bore, or socket 32 is provided in the lower end of the bearing member 23 to communicate with the opening in the shoe Id. The counter bore or socket 32 is preferably of substantially the .same diameter as the com: municatin'g socket 2| of the shoe l8.

.The core catcher I3 is an important feature of the present invention and is adapted to grip catcher is actuated. The core catcher body 33 has suitable clearance in the. sockets 32 and 2| and its internal diameter is such that itreadily receives and passes the core during the coring operation. The body 33 is preferably formed of two telescopically'assembled rings 34 and 35. The inner ring 34 pro ects downwardly beyond the lower end of the outer ring'and the two rings are connected by spaced rivets 36. The upper end of the core catcher body 33 is adapted to engage the upper wall of the socket 32 to limit the upward movement of the core catcher. surfaces of the rings 34 and 35 have annular grooves forming an annular opening 31. A plu- The abutting provided in the upper inner wall of the core catcher body 33 and intersect the annular opening 31.

The core catcher I3 includes a plurality of pivo'ted spring urged dogs 39 for assisting in breaking free the core and supporting the core. The dogs 39 are can'ied by the core catcher body 33 being pivotally mounted in the recesses 38. Pivot pins 40 extend through transverse openings in the dogs 39 and have their opposite ends received in the annular opening 31 to support the dogs 39 for pivotal movement. The portions of the pivot pins 40 received in the opening 31 may be flattened to some extent so that their engagement with the walls of the opening 31 hold the pins against turning and longitudinal movement. The dogs 39 pivotally supported, as just described, are

movable or pivotable between projecting positiems such as illustrated in the drawings where they project inwardly to engage the core, and retracted positions where they are received in the recesses 35 to permit the free passage of the core through the core catcher. If desired or found practical the dogs 39 may be of different lengths. as illustrated, to be efl'ective in acting on hard. full sized cores as well as softer cores of smaller diameter. The active ends of the dogs 39 are pointed or sharpened to efiectively bite into' the core. The dogs 39 have lower faces 4| which are adapted to rest on or engage the lower walls of i the recesses 38 to stop the downward pivotingof the dogs and support them in their .core retaining positions. Notches 42 are provided in the outer or pivoted ends of the dogs 39. Springs 43 in the notches 42 surround the pivot pins 46 and react against the dogs 39 and the body 33 to yieldingly urge the dogs to their projected or actuated positions. Cam parts 44 may be provided on the outer ends of the dogs 39 to cooperate with a shoulder 45 on the interior of the shoe A i6 to assist in pivoting the dogs to their fully 'ture actuation of the slips.

projected positions when the core catcher is actuated.

In accordance with the invention the improved core catcher includes slips 46 located abovethe core catcher body 33 where they do not interiere with the free entrance of the core into the tool. The slips 46 are disposed in the longitudinal opening of the bearing member 26 and have inclined outer surfaces 41 for engaging the inclined surface 3| of the member. The inner sides of the slips 46 are provided with gripping teeth 46 for biting or gripping into the core. The slips 46 are circumferentially spaced and are normally or in-,

preferably counter sunk in the internal surface of the core catcher body. The spring members or flexible members 59 extend upwardly through the opening 30 and their upper portions may be normally inclined upwardly and outwardly to be substantially parallel with the surface 81. The flexible members d9 are attached to the outer or rear sides of the gripping slips 66 by rivets or the like. The members-d9 are preferably recessed or; counter sunk in the outer surfaces of the slips H} merit of the slips with the surface 3!. The flexible members d9 may normally urge the slips d6 outwardly through their inherent resiliency to hold the slips in engagement with the inclined surface 33 and thus assist in preventing prema- In the drilling or coring operation circulation fluid is pumped downwardly through the drilling string and flows downwardly through the annular passage 25. The ports 29 conduct the fluid from the passage 25 to the passage 21. Spaced ports 5d are provided in the hit head shoe idand extend downwardly from the lower end of the passage 27 to the recesses 25 where they discharge the fluid against the cutters 2 3.

Fig. 6 of the drawings illustrates an alternative or modified form of construction. In the construction shown in Fig. 6 of the drawings the shoe 58 of the bit head has an internal thread 63 in the upper portion of its socket 2!. The bit head sub it is threaded on the lower end of the sub id and has a pin 8i at itslower end Provided with a thread for cooperating with the thread dd of the bit head. The lower end of the pin 6| 7 presents a downwardly facing annular shoulder 62. The interior of the lower portion or pin portion of the sub it has a downward y and inwardly inclined surface 63 similar to the surface 3!. An annular upwardly facing shou der 64 occurs at the upper end of the surface 3| and a similar shoulder 80 is provided on the interior of the sub i6 above the shoulder 64.

It is a feature of the construction illustrated in Fig. 6 cf the drawings that a sleeve 66 is welded or otherwise fixed to the shoulder 86 to extend end of the shoe it.

so that they do not interfere with the engage-- v of the sub l4 when the engagement of the inner barrel with the core tends to hold it against downward movement as the drill is fed into the formation. The core catcher l3 described above may be embodied in or employed in combination with the construction shown in Fig. 6 of the drawings. The core catcher i3 is arranged so that its body 33 is in the socket 2| of the shoe i8 below'the shoulder 62. The gripping slips 46 are within the pin portion or lower portion of the sub i6 and are adapted to be actuated through cooperation with the inclined surface 63. The sleeve 65 is important as it provides the sub l6 with theannular fluid passage 66 which conducts the circulation fluid with a minimum of erosion to the sub. Short ports are provided in the sub l6 to extend downwardly from the lower end of the passage 66 to communicate with an annular groove H in the upper Discharge ports l2 conduct the circulation fluid downwardly from the groove ii to the'cutting parts. Short ports'l3 of coinparatively large fluid capacity are provided in the bearing member 67 to conduct the circulation fluid downwardly from the annular passage 25 tothe annular passage 66. It is believed that it will be apparent how the circulation fluid is conducted past or around the rotatable mountin of the inner barrel i2 and the 'corecatcher is without subjecting the parts to appreciable wear or erosion.

During operation of the core drill illustrated in Figs. 1 to 5, inclusive, of the drawings, the cutters 23 engage the formation at the bottom of the well bore and make an annular out leaving a corewhich is received in the bit head opening 26 with suitable clearance. As the drilling progresses the core extends throughthe core catcher i3 and enters the inner barrel i2. upper end of the core enters the core catcher body 33 it is enga'ged by the pivoted dogs 39. The en gagement of the dogs 39 with the upper end of the core usually causes the core catcher to move upwardly to its fully retracted position in the event the core catcher may have worked downwardiy to a position where its slips 66 are actuated. In the event, however, the slips '46 have become prematurely actuated and are not freed by the engagement of the core 'with.the dogs 39 the engagement of the upper end of the core with the actuated slips &6 readily shifts. the slips to their retracted positions without injuring or breaking the flexible members it. The engagement of the upper end of the core. with the actua ed slips d5 merely places the flexible members 49 under anupward strain or a tensile strain which they can sustain without danger of failure. Thus it will be seen that the slips 46 in being disposed above the core catcher body 33 are readily and automatically retracted when the drill enters the core catcher without subjecting any parts of the core catcher to breakage.

When a' core of sufficient length has been drilled the drill is raised or moved upwardly to actuate the core catcher. l3. Upward movement of the drill causes the sharpened pivoted dogs 39 When the I to bite into the core which prevents or resists upclined surface 3i on the upwardly moving tool cooperates with the outer surfaces of the slips 46 to actuate the slips inwardly into tight gripping and holding engagement with the core. The engagement of the dogs 39 and the slips 46 with the core causes the core to be broken free from the formation. The dogs 39 and the slips 68 are adapted to dependably retain the core in the drill as the drill is withdrawn from the well bore. Having described only typical preferred forms and applications of our invention we do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described our invention, we claim: 1 In a core drill having a tubular bit head for making an annular cut in the earth formation and an inner barrel for receiving the core, the combination of, a tubular bearing member secured to the lower end of the inner barrel rotatably bearing in the head to support the inner barrel. and a core catcher including a body rotatably arranged'at the lower end of the member,

. and gripping members connected with the body ably bearing inner barrel, and a core catcher including a body and disposed in the member to be actuated against the core through cooperation with the member.

2. In a core drill having a tubular bit head for making an annular cut in the earth formation and an inner barrel for receiving the core, the combination of, a tubular bearing member secured to the lower end of the inner barrel rotatably bearing in the head to support the inner barrel, and a core" catcher including a body rotatably arranged at the lower end of the member, flexible arms extending upwardly'from the body into the member, and slips on the arms disposed in the member to be actuated against the core through cooperation with the interior of the member.

3. In a core drill having a tubular bit head for making an annular cut in the earth formation and an inner barrel for receiving the core, the

combination of, a tubular bearing member secured to the lower end of the inner barrel rotatin the head to support the head for making an'annular cut in the earth formation andthus leave a core, a tubular connecting member attached to and extending upwardly from the head to connect the head with an outer barrel, an inner barrel for receiving the core, and a bearing member on the lower end of the inner barrel rotatably bearing in the head to support the inner barrel, the bearing member ex-- tendng' through the connecting member with clearance to leave an annular passage therein for receiving the down flowing circulation fluid from the outer barrel, there being discharge ports in the head receiving the fluid from the passage.

5. In a core drill construction, a tubularrbit head for making an annular cut in the earth formation and thus leave a core, a tubular connecting member attached to and extending up- .wardly from the head to connect the head with an outer barrel, an inner barrel for receiving the core, and a bearing member on the lower end of the inner barrel, the bearing member extending through the connecting member with clearance to leave an annular passage therein for receiving the down flowing circulation fluid from the outer barrel, there being discharge ports in the head receiving the fluid fromthe passage, there being a counter bore in the lower end of the bearing member communicting with and forming a continuation of the central opening of the tubular head.

6. In a core drill construction having a head for making an annular cut in the earth formation and a tubular connecting member attached to and extending upwardly from the head to connect the head with anouter barrel, the combination'of an inner barrel for receiving the core, a tubular bearing member attached to the lower end of the inner barrel for rotatably bearing in the head to support the inner barrel, the bearing member extending through the connecting member with clearance to leave an annular passage for receiving the down flowing circulation fluid from the outer barrel, and an inclined face on the interior of the hearing member for actuating core gripping slips.

7. In a core drill construction having an inner barrel for receiving the core, the combination of, a tubular bearing member secured to the lower end of the inner barrel for rotatably supporting the inner barrel, an inclined face on the interior of the bearing member, a core catcher body rotatable in the bearing member, flexible arms extending upwardly from the said body, and slips on the arms operable inwardly to grip the core through cooperation with said face.

8. In a core drill construction, a tubular bit head for making an annular cut in the earth formation, an outer barrel adapted to be connected to a drilling string, a tubular connecting member connecting the bit head with the outer barrel, an inner barrel extending through the outer barrel with clearance to leave an annular fluid passage and supported in the, bit head, there being fluid discharge ports in the bit head, and a sleeve rigidly secured to the connecting member in spaced relation to its interior leaving an annular space which connects the annular fluid passage with the ports.

9. In a core drill having a barrel and bit head with fluid discharge ports therein, a tubular member for connecting the bit head with the lower end of the barrel,.and a sleeve rigidly secured to the member in spacedrelation to its internal wall leaving an annular passage communicating with the interior of the barrel, there being ports in the member connecting the lower end of the annular passage with the ports in the head.

10. A core catcher for use in a core drill having an inclined internal surface including a body adapted to be movably arranged in the drill below said surface, flexible members attached to the body and projecting upwardly therefrom, and

core gripping slips on the flexible members actuated through cooperation with the said surface.

11. Acore-catcher for use in a core drill having an inclined internal surface including a body adapted to be movably arranged in the drill below said surface, a flexible member attached to the body and projecting upwardly therefrom, and a core gripping slip on the upper end of the flexible member operable inwardly togrip a core through cooperation with said surface on rela-.

tive movement between the drill and body.

12. A core catcher for use in a core drill having an inclined internal surface including a. body adapted to be arranged in the drill for relative movement, means on the body for engaging a core to resist movement of the body relative to the core, a flexible member secured to the body and relative to the core, a flexible member secured to 15 the body and projecting upwardly therefrom, and a core gripping slip on the upper portion of the flexible member actuated inwardly to grip a core by cooperation with said surface on upward movement of the drill relative to the body.

14. A core catcher for use in a core drill having an inclined internal surface including a body adapted to be arranged in the drill for relative movement, means on the body for engaging a core to resist movement of the body relative to 25 the core, a flexible member secured to the body and projecting upwardly therefrom, and a core gripping slip on the upper portion of the flexible member urged against said surface by the resil iency of the member and actuated inwardly by v said surface when the drill is moved vertically relative to the body.

15. A core catcher for use in a core drill having an inclined internal surface including a body adapted to be arranged'in the drill below said surface for movement relative to the drill, core gripping dogs on the body adapted to engage the core to hold the body against movement when the drill is moved, flexible members secured to and projecting upwardly from the body, and slips on the members operable inwardly to grip a core by said surface on vertical movement of the drill relative to the body.

16. A core catcher for use in a core drill having an inclined internal surface including a body adapted to be arrangedin the drill below said surface for vertical movement and rotation, core gripping dogs on the body, spring means urging the dogs inwardly against the core to resist move- "ment of the body relative to the core, flexible members attached to the body and projecting upv wardly therefrom, and slips on the flexible members operable inwardly by said surface to grip the core on relative movement between the drill and body.

ALFRED C. CATLAND. JOHN H. HOWARD. 

